Gosukon by author Fuyu Naga is a manga about a girl called Hamada Ari who wears Gothic Lolita clothes, which somehow finds herself involved in various boxing matches, she's meek and weak until she sees her own blood at which point she transform into a bloody thirsty demon
Plus Size Elf is a comedy manga with a rather unique premise, where in standard fantasy trope elves are seen as slim and graceful the one in this manga is a chubby lazy slob who's obsessed with french fries, she then tries various method of dieting including boxercise
Kick no Oneesan/Kick The Girl is a romcom about a salaryman who falls for a cute Kickboxer girl (can you say, ONE OF US! ONE OF US!) this manga and saotome senshu are similar in premise, but this is more of a com than a rom